An intractable minority of humans are filled with hate, resentment and a will to do harm to those they perceive as different. Nothing is likely to change that core malignancy. Yet the modern world gives those intent on harm the tools to carry out their deeds and the means to recruit and incite others to the same — a billion guns, a worldwide system of instant, unlimited communication through the internet, and leaders who gain power by stoking hate and differences, leaders such as President Trump.

There is no way to stop these increasing outbreaks until all nations decide for the common good and survival of humanity to severely regulate or even ban guns; to limit internet speech that incites violence and hatred; and to reject overwhelmingly candidates whose core message elevates one people over another. Attempts to identify likely perpetrators and keep guns out of their hands are as foolhardy as attempts to kill or imprison all of the terrorists.

I must admit that I am of two minds about the rapid viral spread of video of a mass shooting and attempts to stop its distribution. On the one hand, it is horrible that someone can not only commit such senseless snuffing of lives but also record the horror in real time, so that others can experience the suffering and terror and be traumatized at a remove.

But — and I realize this likely won’t be a popular viewpoint — should we so quickly attempt to censor and muzzle such recordings? Should they not be there to remind us of the depths to which we can sink, and to remind us what we’re up against? Should we not be able to view it in the same way we view pictures and video taken of the World War II concentration camps, so we can all bear witness and never forget?

I realize that there is the argument that allowing this to be shown just encourages the next nihilist. But there is also the argument that we all need to know that this mind-set exists and fight against “out of sight, out of mind” denial, and that witnessing horror can galvanize action for good as well as for evil.

I admit that I don’t know where the balance lies.

Glenn RibotskyElmhurst, Queens

A version of this article appears in print on , on Page A24 of the New York edition with the headline: Deadly Mosque Attacks in New Zealand. Order Reprints | Today’s Paper | Subscribe